Detergent enzymes have been marketed for more than 20 years and are now well established as normal detergent ingredients in both powder and liquid detergents all over the world.
Enzymes used in washing formulations comprise many different enzymes such as proteases, lipases, amylases, cellulases, as well as other enzymes, or mixtures thereof. Commercially the most important enzymes are the proteases.
Detergent proteases have been developed by isolation of proteases found in nature followed by testing in detergent formulations. Most detergent proteases are obtained from members of the genus Bacillus.
Examples of commercial protease products are ALCALASE.TM., ESPERASE.TM. and SAVINASE.TM., all supplied by Novo Nordisk A/S, Denmark. The ALCALASE.TM. protease is produced by strains of the species Bacillus licheniformis. The ESPERASE.TM. and SAVINASE.TM. proteases are obtained by cultivation of strains of alkalophilic Bacilli.
The washing traditions, especially the used washing temperature, the hardness of the used water, and the ingredients of the detergents vary very much from one country to another. Typical conditions are outlined below:
low pH and low water hardness: liquid detergents in US and Asia; PA1 low pH and high water hardness: liquid detergents in Europe; PA1 high pH and low water hardness: powder detergents in US and Asia; and PA1 high pH and high water hardness: powder detergents in Europe.
(A low pH in detergents is typically a pH in the range 8.0-9.5, in particular around 9; a high pH in detergents is typically a pH in the range 10-11.5, in particular around 10.5. A low water hardness is typically in the range 3.degree.-6.degree. dH; a high water hardness is typically in the range 15.degree.-20.degree. dH, in particular around 18.degree. dH).
Furthermore, the compositions of the detergents are changing these years in order to make the washing process more environmental friendly. All these differences and changes within the detergent industry make the field extremely complicated. There is therefore a need all the time to find new proteases which perform optimally at a certain specified set of conditions.